Environ Sci Pollut Res DOI 10.1007/s11356-014-3180-5

WORLDWIDE INTEGRATED ASSESSMENT OF THE IMPACT OF SYSTEMIC PESTICIDES ON BIODIVERSITY AND ECOSYSTEMS

A review of the direct and indirect effects of neonicotinoids and fipronil on vertebrate wildlife

David Gibbons & Christy Morrissey & Pierre Mineau

Received: 7 April 2014 /Accepted: 6 June 2014 # The Author(s) 2014. This article is published with open access at Springerlink.com

Abstract Concerns over the role of pesticides affecting ver- at levels below those which will cause mortality to freshwater tebrate wildlife populations have recently focussed on system- vertebrates, although sub-lethal effects may occur. Some re- ic products which exert broad-spectrum toxicity. Given that corded environmental concentrations of fipronil, however, the neonicotinoids have become the fastest-growing class of may be sufficiently high to harm fish. Indirect effects are insecticides globally, we review here 150 studies of their direct rarely considered in risk assessment processes and there is a (toxic) and indirect (e.g. food chain) effects on vertebrate paucity of data, despite the potential to exert population-level wildlife—mammals, birds, fish, amphibians and reptiles. We effects. Our research revealed two field case studies of indirect focus on two neonicotinoids, imidacloprid and clothianidin, effects. In one, reductions in invertebrate prey from both and a third insecticide, fipronil, which also acts in the same imidacloprid and fipronil uses led to impaired growth in a fish systemic manner. Imidacloprid and fipronil were found to be species, and in another, reductions in populations in two lizard toxic to many birds and most fish, respectively. All three species were linked to effects of fipronil on termite prey. insecticides exert sub-lethal effects, ranging from genotoxic Evidence presented here suggests that the systemic insecti- and cytotoxic effects, and impaired immune function, to re- cides, neonicotinoids and fipronil, are capable of exerting duced growth and reproductive success, often at concentra- direct and indirect effects on terrestrial and aquatic vertebrate tions well below those associated with mortality. Use of wildlife, thus warranting further review of their environmental imidacloprid and clothianidin as seed treatments on some safety. crops poses risks to small birds, and ingestion of even a few treated seeds could cause mortality or reproductive impair- Keywords Pesticide . Neonicotinoid . Imidacloprid . ment to sensitive bird species. In contrast, environmental Clothianidin . Fipronil . Vertebrate . Wildlife . Mammals . concentrations of imidacloprid and clothianidin appear to be Birds . Fish . Amphibians . Reptiles . Risk assessment

Responsible editor: Philippe Garrigues D. Gibbons (*) Overview of impacts of pesticides on vertebrate wildlife RSPB Centre for Conservation Science, RSPB, The Lodge, Sandy, Bedfordshire SG19 2DL, UK Although vertebrates are the intended target of only 2 % of e-mail: [email protected] pesticides on the market, the unintentional impacts of pesti- C. Morrissey cides on vertebrate populations have been marked and are Department of Biology, University of Saskatchewan, 112 Science well documented (e.g. Sánchez-Bayo 2011). Pesticides can Place, Saskatoon, Saskatchewan S7N 5E2, Canada exert their impact on vertebrates either directly, through their toxicity, or indirectly, for example, by reducing their food C. Morrissey School of Environment and Sustainability, University of supply. Saskatchewan, 117 Science Place, Saskatoon, Saskatchewan S7N Direct effects may be the result of several different expo- 5E2, Canada sure pathways: through ingestion of the formulated product (e.g. birds eating seeds coated with insecticide; Avery et al. P. Mineau Pierre Mineau Consulting, 124 Creekside Drive, Salt Spring 1997; Prosser and Hart 2005), through uptake via the skin Island V8K 2E4, Canada following a spray event (Mineau 2011) or by eating Environ Sci Pollut Res contaminated prey. Probably the most notable example among acetylcholine receptors (nAChR) in the postsynaptic neuron, the latter exposure pathway was the dramatic impact that acting as ‘false neurotransmitters’ (agonists). This interference organochlorine pesticides, especially DDT and its metabolite with acetylcholine neurotransmitter signalling causes contin- DDE, had on populations of birds of prey (Ratcliffe 1967; uous activation of the receptor, leading to symptoms of neu- Newton 1995). Depending on the extent of intoxication, direct rotoxicity. Neonicotinoids have greater affinity for, and thus effects of pesticides can either kill vertebrates outright or exert bind more strongly to, insect than mammalian or other verte- sub-lethal effects, for example, on growth and reproduction brate receptors, so their toxicity to mammals is lower than it is (Sánchez-Bayo 2011). Progress since the organo-chlorine era to insects and the reversibility of intoxication higher has helped ensure that compounds that are currently being (Tomizawa and Casida 2005; Jeschke et al. 2011). Fipronil developed and registered are generally less persistent and do works similarly, but instead binds to the gamma-aminobutyric not as readily bio-accumulate in food webs. acid (GABA) receptors, resulting in similar continuous central More recently, however, interest has turned to investigating nervous system activity (Tingle et al. 2000, 2003). As with the potential for indirect effects which are typically mediated neonicotinoids, fipronil has a lower affinity to vertebrate than through loss in quantity or quality of prey associated with to invertebrate receptors (Grant et al. 1998). Despite the lower pesticide use, or through habitat modification (Sotherton and toxicity of these products to vertebrates than to invertebrates, Holland 2002; Boatman et al. 2004;Morrisetal.2005). This there is still ample evidence that vertebrates show toxic ef- is especially the case in jurisdictions where the use of highly fects, albeit at markedly higher concentrations than for many toxic pesticides has been controlled and the frequency of target and non-target invertebrate species (e.g. Tingle et al. direct impacts reduced (Mineau et al. 1999). 2000, 2003; Cox 2001; SERA 2005; DeCant and Barrett Over the last 2 decades, a new class of insecticides, the 2010; Mineau and Palmer 2013). neonicotinoids, has become the most important and fastest growing of the five major chemical classes of insecticides on the global market (Jeschke and Nauen 2008; Jeschke et al. Materials and methods 2011; Tomizawa and Casida 2011;CasidaandDurkin2013). When used as plant protection products, neonicotinoids act by To assess the likely impacts of neonicotinoids and fipronil on becoming distributed systemically throughout the growing vertebrates, a literature search was undertaken using Web of plant following seed or soil applications. Another recent in- Science and Google Scholar. Search terms were [product] and secticide, fipronil, a phenyl-pyrazole (fiprole) rather than a [taxon], where [product] was either neonicotinoid, neonicotinoid, also acts in the same manner and has a similar imidacloprid, thiacloprid, clothianidin, thiamethoxam, toxicity and persistence profile (Grant et al. 1998). Conse- acetamiprid, nitenpyram, dinotefuran or fipronil; and [taxon] quently, the neonicotinoids and fipronil are sometimes jointly was either vertebrate*, mammal*, bird*, reptile*, amphibian* termed ‘systemic insecticides’, although there are also older and fish*. In addition, specific searches were made on a few products which could be termed ‘systemic’, for example, the common toxicity test species (e.g. rat) and by following up organo-phosphorous insecticide acephate and the organo- references cited in the publications found by the search. The arsenical, monosodium methanearsonate. Neonicotinoids review also draws heavily on the recently published report by are, in particular, commonly applied as seed treatments. The Mineau and Palmer (2013) on the direct and indirect toxicity use of seed treatments as a convenient and effective applica- of neonicotinoids to birds. Several industry studies, which tion method has widespread appeal in the farming industry. have not been formally published but which were part of Consequently, systemic seed treatments are now used on the product approval processes, were reviewed by Mineau and majority of agricultural crops worldwide (Garthwaite et al. Palmer and have been included here. While industry studies 2003; Jeschke et al. 2011). have been reviewed by regulators and may receive as much Here, we build on the reviews of others (e.g. Goulson 2013; critical review as in the open peer-reviewed literature, empha- Köhler and Triebskorn 2013; Mineau and Palmer 2013)to sis here is on published reports and the primary literature. examine the evidence and potential for direct and indirect The following information was extracted from each study: effects of two common systemic neonicotinoid insecticides, the product used, its dose and whether or not it was presented imidacloprid and clothianidin, along with fipronil on verte- as a single dose (acute) or over a period of time (chronic; e.g. brate wildlife. over 30 days); the effects on individual organisms, specifically whether there was an impact on survival, reproduction, growth and development, or other sub-lethal effects, such as Mode of action of the systemic insecticides neurobehavioural, genotoxic, cytotoxic, and immunotoxic; the impact on populations of the animal (e.g. local popula- Neonicotinoids work by interfering with neural transmission tions); the type of study, separated into laboratory or field; and in the central nervous system. They bind to the nicotinic finally whether it was a study of direct toxic effects, or indirect Environ Sci Pollut Res effects (e.g. leading to changes in food availability). In some The US Environmental Protection Agency has developed cases, individual studies covered more than one species, and an ecotoxicity classification based on LD50 and LC50 assess- each is treated here as a separate species impact study. ments (US EPA 2012). They classify the acute toxicity of a The great majority of the studies were laboratory-based given product on a particular species as either practically non- (139/152=91 %) and most (146, 96 %) were direct toxicity toxic, slightly toxic, moderately toxic, highly toxic, or very studies. While common in ecotoxicology, the lack of field highly toxic based on lethality dose ranges. Sub-lethal or testing and over-reliance on laboratory direct toxicity testing reproductive effects are not included in this classification. limit our ability to interpret the findings under field-realistic By US EPA’s definitions, and within the highly restricted conditions. Field experiments have provided some of the most range of species assessed, imidacloprid shows moderate to compelling evidence of the impact of neonicotinoids on pop- high toxicity to birds, particularly for smaller-bodied species ulations in their natural environment (e.g. Whitehorn et al. such as house sparrows, Passer domesticus, and canaries, 2012), and there is an increasing recognition that maintaining Serinus canaria, and approaches very high toxicity to grey ecological complexity in field studies is desirable partridge, Perdix perdix. It is moderately toxic to rats and (Suryanarayanan 2013). mice, but practically non-toxic to fish (with the exception of The most common study taxa were mammals (58), birds rainbow trout, especially their fry) and amphibians. (47) and fish (32), with substantially fewer studies of amphib- Clothianidin’s toxicity ranges from moderate to practically ians (12) and reptiles (3). Within these individual taxa, the non-toxic for both birds and mammals, whereas for the fish most commonly studied mammals were rat, Rattus studied, it varies from slightly toxic to practically non-toxic. norvegicus, (39) and mouse, Mus musculus, (9); the most By contrast, for all fish species studied, fipronil is either highly commonly studied birds were northern bobwhite quail, or very highly toxic (e.g. bluegill sunfish, Lepomis Colinus virginianus, (8) and mallard, Anas platyrhynchos, macrochirus). Fipronil is in addition highly toxic to the three (6), the two test species mandated by regulatory approval game birds studied (red-legged partridge, Alectoris rufa,ring- schemes in North America; and the most commonly tested necked pheasant, Phasianus colchicus, and northern bobwhite fish were rainbow trout, Oncorhynchus mykiss, (6) and Nile quail), and moderately toxic to mice and rats. tilapia, Oreochromis niloticus,(6). One of the serious failings of current risk assessments is the Most of these studies investigated the effects of the two underestimation of interspecies variation in insecticide sus- neonicotinoids, imidacloprid (72) and clothianidin (19), as ceptibility that is apparent from Table 1. Too few species are well as fipronil (47); between them, these three insecticides typically tested to derive the true variation in response from accounted for 91 % of all studies. Given the paucity of the vast array of exposed species in the wild. Mineau and information collated for the other neonicotinoids, this review Palmer (2013) discuss this at length for neonicotinoids and concentrates on these three products alone. propose improved thresholds derived from species sensitivity

distributions and estimated ‘hazard doses’ (HD5—the LD50 value for a species at the 5 % tail of the sensitivity The direct effects of neonicotinoids and fipronil distribution). on vertebrate wildlife

Toxicity to vertebrates Impacts on growth, development and reproduction of vertebrates Standard toxicity testing for pesticides on terrestrial vertebrates is through an acute (<96 h) study. Test organisms are given the While not necessarily causing mortality among adults, intox- product by gavage (i.e. through a feeding tube) or through the ication by imidacloprid, clothianidin and fipronil can reduce diet in varying concentrations, and the estimated dose of the growth, development and reproduction of individual ver- pesticide associated with death of half of the test subjects is tebrates (Table 2). Reproductive effects are manifest in a recorded and expressed as a proportion of bodyweight (i.e. the variety of ways among mammals, but especially as reduced

50 % lethal dose, LD50, expressed as milligrams of pesticide sperm production, adverse effects on the fertilization process, per kilogram of bodyweight). Toxicity for aquatic organisms is reduced rates of pregnancy, higher rates of embryo death, typically measured as the LC50 or the concentration in water stillbirth and premature birth, and reduced weights of off- (e.g. mg/L) which is toxic to the test organisms. Numerous spring. Among birds, testicular anomalies and reduced fertil-

LD50 and LC50 tests have been undertaken for vertebrates, and ization success, reduced eggshell thickness and embryo size, those that were located as part of this review are shown for reduced hatching success and chick survival, and chick devel- imidacloprid, clothianidin and fipronil in Table 1.Ascanbe opmental abnormalities have all been reported. Weight loss, or seen, the relative toxicity of these products varies, both among impaired weight gain, sometimes associated with reduction or products and among species. cessation of feeding, occurred within all taxa studied. Environ Sci Pollut Res

Table 1 Single (acute) dose LD50 (for mammals birds and reptiles, mg/kg) and LC50 (for fish and amphibia, mg/L) for imidacloprid, clothianidin and fipronil

Taxon Species Imidacloprid Clothianidin Fipronil

Mammal Rat, Rattus norvegicus 425-475 (MT)a 5,000 (PNT)i 97 (MT)l Mouse, Mus musculus 131-300 (MT)a >389 (MT)i 95 (MT)m Bird Mallard, Anas platyrhynchos 283 (MT)b >752 (ST)j 2,150 (PNT)l Ring-necked pheasant, Phasianus colchicus 31 (HT)l Grey partridge, Perdix perdix 13.9 (HT)c Red-legged partridge, Alectoris rufa 34 (HT)l Northern bobwhite quail, Colinus virginianus 152 (MT)a >2,000 (PNT)k 11.3 (HT)l Japanese quail, Coturnix japonica 31 (HT)a 423 (MT)k Feral pigeon, Columba livia 25–50 (HT)a >2,000 (PNT)l House sparrow, Passer domesticus 41 (HT)a Field sparrow, Spizella pusilla 1,120 (ST)l Canary, Serinus canaria 25–50 (HT)a Zebra finch, Taeniopygia guttata 310 (MT)n Fish Bluegill sunfish, Lepomis macrochirus 105 (PNT)a >117 (PNT)i 0.083 (VHT)l Japanese carp, Cyprinus carpio 0.34 (HT)l Nile tilapia, Oreochromis niloticus 0.042-0.147 (VHT-HT)l Rainbow trout, Oncorhynchus mykiss >83–211 (ST-PNT)a >105 (PNT)i 0.246 (HT)l Rainbow trout (fry) 1.2 (MT)d Sheepshead minnow, Cyprinodon variegatus 161 (PNT)a >93.6 (ST)i 0.13 (HT)l Zebrafish, Danio rerio 241 (PNT)e Amphibia Black-spotted pond frog, Rana nigromaculata 129–219 (PNT)a,f Indian rice frog, Rana limnocharis 82–366 (ST-PNT)a,f,g Western chorus frog, Pseudacris triseriata 194 (PNT)h American toad, Bufo americanus 234 (PNT)h Reptile Fringe-toed lizard, Acanthodactylus dumerili 30 (HT)o

Toxicity classification follows US EPA (2012): PNT practically non-toxic, ST slightly toxic, MT moderately toxic, HT highly toxic, VHT very highly toxic. For birds, mammals and reptiles: PNT >2,000, ST 501–2,000, MT 51–500, HT 10–50, VHT <10. For aquatic organisms, fish and amphibia: PNT >100, ST >10-100, MT >1-10, HT 0.1-1, VHT <0.1. Note that kg in the LD50 units refers to body weight of the dosed animal. Source references denoted by superscripts are as follows: a SERA 2005, b Fossen 2006, c Grolleau 1991 in Anon 2012, d Cox 2001, e Tisler et al. 2009, f Feng et al. 2004, g Nian 2009, h Howard et al. 2003, i DeCant and Barrett 2010, j European Commission 2005, k Mineau and Palmer 2013, l Tingle et al. 2003, m Connelly 2011, n Kitulagodage et al. 2008 (NB : a formulation of fipronil containing the dispersant solvent diacetone alcohol was sevenfold more toxic than technical grade fipronil itself), o Peveling and Demba 2003 (NB: 42 %, rather than 50 %, mortality)

Most of the studies found were required for pesticide realistic exposure in the wild. However, it remains the only registration purposes. In birds, a reproductive test is frequently test available with which to model non-acute risk in avian conducted on standard test species such as the northern bob- wildlife. white quail or the mallard. This is a truncated test, which consists of feeding a constant concentration of the pesticide Other sub-lethal impacts on vertebrates to the study animals and then collecting the eggs and incubat- ing them artificially. There is therefore no inclusion of end- A range of other effects of these insecticides have been doc- points to assess the ability of the dosed birds to incubate, hatch umented for vertebrates (Table 2), outside of those reported on or raise their young. The test is a hybrid between single life survival, growth and development, and reproduction. Among stage chronic toxicity and a test of true reproductive effects, mammals—principally rats and mice—these include and has been the subject of analysis and criticism (Mineau genotoxic and cytotoxic effects, neuro-behavioural disorders et al. 1994, 1996; Mineau 2005). Because of the longer of offspring (including those dosed in utero), lesions of the duration of the test, and the occasional pair that fails to bond, thyroid, retinal atrophy, reduced movement, and increased spurious variance is introduced, thus decreasing the power to measures of anxiety and fear. House sparrows can become detect reproductive deficits in limited sample sizes. On the uncoordinated and unable to fly, and studies of Japanese quail other hand, because the birds are offered contaminated diet and red-legged partridges have reported DNA breakages and a only, with no other food choice, the test may overestimate reduced immune response, respectively. Similarly, studies of nio c oltRes Pollut Sci Environ Table 2 Other studies of the direct effects of imidacloprid, clothianidin and fipronil on vertebrates

Taxon and species Effect on: Imidacloprid Clothianidin Fipronil Source and detailed effect

Mammal a Rat, Rattus norvegicus Reproduction 2, 19, 90 mg/kg/daya,b,c 24, 31.2–36.8 mg/kg/ 280 mg/kgf Baletal.2012; reduced sperm production dayd,e 26–28 mg/kg/ bCox 2001; reduced weight offspring dayg cGawade et al. 2013; abortions, soft tissue abnormalities and skeletal alterations dBaletal.2013;noeffectonsperm concentration, mobility or morphology, but reduced weight of epididymis and seminal vesicles eDeCant and Barrett 2010; stillbirths and delayed sexual maturation fOhietal.2004; reduced levels of pregnancy gTingle et al. 2003; range of effects including reduced fertility and decreased litter size Rat, Rattus norvegicus Growth and 10,17,25,100 mg/kg/ 31.2 mg/kg/daye 20 mg/kg/daygaCox 2001; reduced weight gain development daya,b,c,d 32 mg/kgf bCox 2001; thyroid lesions cBhardwaj et al. 2010; reduced weight and locomotor ability dCox 2001; atrophy of retina eDeCant and Barrett 2010; reduced weight gain of offspring fBaletal.2012; reduced body weight and impact on reproductive organs gTingle et al. 2003; reduced food consumption and reduced weight gain Rat, Rattus norvegicus Genotoxic 300 mg/kga 24 mg/kg/dayb(NE) aDemsia et al. 2007;significanteffectonin vitro micronucleus induction in rat erythrocytes bBaletal.2013;noeffectonspermDNA fragmentation a Rat, Rattus norvegicus Cytotoxic <400 mg/kga Nellore et al. 2010; blocks to the cholinergic 0.21,1,20,45 mg/kg/ enzyme system dayb,c,d,e bMohany et al. 2011; oxidative stress and hepatotoxicity, i.e. heavily congested central vein and blood sinusoids in liver cDuzguner and Erdogan 2012; oxidative stress andinflammationcausedbyaltering antioxidant systems dKapoor et al. 2010; oxidative stress eToor et al. 2013; hepatotoxicity—dilations of central vein and sinusoids between hepatocytes in liver a Rat, Rattus norvegicus Neurobehavioural 337 mg/kga >2mMb <30,140-280dermal Abou-Donia 2008; offspring dosed in utero, 18–66 mg/kg/dayc mg/kgd,e led to neurobehavioural deficits Table 2 (continued)

Taxon and species Effect on: Imidacloprid Clothianidin Fipronil Source and detailed effect

bde Oliveira et al. 2010; increased release of dopamine cTanaka 2012; adverse neurobehavioural impacts on pups dMartins 2009; reduced movement eTercariol and Godinho 2011; increased emotion and fear Rat, Rattus norvegicus Immunotoxic 0.21, 90 mg/kg/daya,b a Mohany et al. 2011; significant effect on leukocyte count, immunoglobulins and phagocytic activity bGawade et al. 2013; compromised immunity Mouse, Mus musculus Reproduction 5 mMa 18–66 mg/kg/day (NE)baGu et al. 2013; no impact on sperm mobility, but fertilisation process and zygotes adversely affected bTanaka 2012; no effect on litter size or weight Mouse, Mus musculus Growth and 18–66 mg/kg/day (NE) Tanaka 2012; no effect on litter size or weight development Mouse, Mus musculus Genotoxic 5 mM (NE) Gu et al. 2013; no effect on DNA integrity Mouse, Mus musculus Immunotoxic 10 mg/kg/day Badgujar et al. 2013; suppressed cell-mediated immune response and prominent histopathological alterations in spleen and liver Rabbit, Sylvilagus sp. Reproduction 72 mg/kg/daya >25 mg/kg/daybaCox 2001; increased frequency of miscarriage bDeCant and Barrett 2010; increase in premature births Sheep, Ovis aries Growth and 0.5 mg/kg/day Leghait et al. 2010; no thyroid disruption development (NE) Cow, Bos primigenius Cytotoxic 1 mg/kg/day (NE) Kaur et al. 2006; some modest impacts on plasma biochemistry, but mostly no impact on range of other blood measures Bird Mallard, Anas platyrhynchos Reproduction 16 mg/kg/day >35 mg/kg/day (NE) Adapted from figures in Mineau and Palmer (2013)*; various effects on reproduction Chicken, Gallus gallus domesticus Growth and 37.5 mg/kg Kitulagodage et al. 2011b; reduced feeding and development body mass, and developmental abnormalities of chicks

Chicken, Gallus gallus domesticus Neurobehavioural 37.5 mg/kg Kitulagodage et al. 2011b; behavioural Res Pollut Sci Environ abnormalities of chicks Red-legged partridge, Alectoris rufa Survival 31.9-53.4 mg/kg/day Lopez-Antia et al. 2013; reduced chick survival at low dose, and reduced adult survival at high dose Red-legged partridge, Alectoris rufa Reproduction 31.9 mg/kg/day Lopez-Antia et al. 2013; reduced fertilisation rate and chick survival nio c oltRes Pollut Sci Environ Table 2 (continued)

Taxon and species Effect on: Imidacloprid Clothianidin Fipronil Source and detailed effect

Red-legged partridge, Alectoris rufa Immunotoxic 53.4 mg/kg/day Lopez-Antia et al. 2013; reduced immune response Northern bobwhite quail, Colinus Reproduction >52 mg/kg/day Adapted from figures in Mineau and Palmer virginianus (2013)*; various effects on reproduction Northern bobwhite quail, Colinus Growth and 24 mg/kg/daya 11 mg/kgbaAdapted from figures in Mineau and Palmer virginianus development (2013)*; various effects on weight bKitulagodage et al. 2011a; birds stopped feeding so lost weight Japanese quail, Coturnix japonica Reproduction 1 mg/kg/day Tokumoto et al. 2013; testicular anomalies; reductions in embryo length when those males mated with un-dosed females Japanese quail, Coturnix japonica Genotoxic 1 mg/kg/day Tokumoto et al. 2013; increased breakage of DNA in males House sparrow, Passer domesticus Neurobehavioural 6 mg/kg Cox 2001; in-coordination, inability to fly Zebra finch, Taeniopygia guttata Reproduction >1 mg/kg Kitulagodage et al. 2011b; reduced hatching success Fish Japanese carp, Cyprinus carpio Growth & development REC (NE) Clasen et al. 2012; no impact on growth or survival, though biochemical changes Zebrafish, Danio rerio Reproduction 320 mg/L (NE) Tisler et al. 2009; no effect on embryos observed Zebrafish, Danio rerio Growth and 0.33 mg/L Stehr et al. 2006; notochord degeneration development Zebrafish, Danio rerio Neurobehavioural 0.33 mg/L Stehr et al. 2006; locomotor defects in embryos and larvae Fathead minnow, Pimephales promelas Growth and 20 mg/L DeCant and Barrett 2010; reduced weight and length development Fathead minnow, Pimephales promelas Genotoxic 0.03 mg/L Beggel et al. 2012; changes in gene transcription Fathead minnow, Pimephales promelas Neurobehavioural 0.14 mg/L Beggel et al. 2010; impaired swimming; formulation more toxic than technical grade Nile tilapia, Oreochromis niloticus Growth and 0.134, <1.34 mg/La,b a Lauan and Ocampo 2013; extensive development disintegration of testicular tissue. bOcampo and Sagun 2007; changes to gonads Medaka, Oryzias latipes Immunotoxic 0.03–0.24 mg/L Sanchez-Bayo and Goka 2005; juveniles stressed, (1.5*REC) led to ectoparasite infestation, when concentrations high early in the experiment Silver catfish, Rhamdia quelen Genotoxic 0.0002 mg/L Ghisietal.2011; no genotoxic effects (NE) Silver catfish, Rhamdia quelen Cytotoxic 0.0002 mg/L Ghisi et al. 2011; erythrocyte damage Environ Sci Pollut Res

fish have reported changes in gene transcription, erythrocyte damage, disintegration of gonadal tissue, impaired swimming, notochord degeneration and locomotor defects in embryos given dosage, and larvae. In one case, medaka fish, Oryzias latipes,in experimental rice fields became physiologically stressed (characterized by increased anaerobic metabolism leading to hyperglycemia) following exposure to imidacloprid at 1.5 times the commercially recommended rate of application, and subsequently became susceptible to infestation by the leterious effects at the ; DNA damage at very low protozoan ectoparasite, Cychlochaeta (Trichodina) domerguei ct toxicity under laboratory conditions.

2004 (Sánchez-Bayo and Goka 2005). While the majority of studies

pectively documented deleterious impacts from neonicotinoid or fipronil exposure, effective doses have not typically been concentrations matched to realistic field exposure conditions. Many of these, perhaps, more subtle sub-lethal effects tudies demonstrated de (Table 2) occur at much lower concentrations than lethal effects (Table 1). Thus, while single oral doses of 425–475 and 5,000 mg/kg of imidacloprid and clothianidin, respective- onil Source and detailed effect ly, will kill rats, lower daily doses of 0.21–100 and 18– 66 mg/kg/day have consistently caused a range of sub-lethal – s recommended rate; all others are of dire effects. For example, a daily dose of 10 19 or 31 mg/kg/day ’ of imidacloprid and clothianidin, respectively, will cause re- duced growth of young rats and, in the case of clothianidin, a greater frequency of stillbirths. Even doses as low as 0.21 and Lowest feed concentrations causing an effect were transformed to a daily dose assuming an

* 2.0 mg/kg/day of imidacloprid have been shown to have immunotoxic effects and reduce sperm production, respec- tively. Similarly, while a single oral dose of 41 mg/kg of imidacloprid will cause mortality in house sparrows, a sub- or chronic, the latter shown as /day (per day). All s

rd, respectively, and average body weights of 210 and 100 g, res stantially lower dose (6 mg/kg) can induce uncoordinated behaviour and an inability to fly. While imidacloprid is highly

toxic to Japanese quail, with an LD50 of 31 mg/kg, chronic daily doses of only 1 mg/kg/day can lead to testicular anom-

acloprid Clothianidin Fipr alies, DNA damage in males, and reductions in embryo size when those males are mated with control females. The black-

spotted pond frog has an LC50 of 129–219 mg/L of imidacloprid, but DNA damage occurs at a much lower con- centration, 0.05 mg/L. Given the high toxicity of fipronil to fish, it is perhaps not surprising that the lowest recorded

per day for bobwhite quail and malla concentration of that insecticide to affect a vertebrate was of 0.0002 mg/L (0.2 μg/L); the effect being erythrocyte damage

Genotoxic 0.05 mg/Lin silver catfish, Rhamdia Feng et al. quelen. While it is difficult to and not repeated here. Dosage could either be acute es marked REC were field-based, with insecticides applied at the manufacturer extrapolate such sub-organism effects to fitness-related mea- 1 sures in individuals and population-level responses, they offer insight into potential mechanisms underpinning direct toxicity. Rana Different families of pesticides rarely elicit sub-lethal ef- fects at doses below 1/10 of the lethal dose (Callahan and Mineau 2008). But, in the case of imidacloprid, signs of severe debilitation (e.g. ataxia) were observed a full order of magni- tude below lethal doses. Review of available laboratory data (continued) =dermal application. Only studies for which dosage information was readily available are listed.

’ here suggests that some effects can be detected at even lower

nigromaculata doses (1/1,000). This apparent feature of these insecticides is Black-spotted pond frog, dermal Amphibia average consumption of 21- and 67-g laboratory feed except those marked NE (no effect). Studi Table 2 Taxon and species Effect on: Imid Acute toxicity studies are given in Table ‘ of toxicological concern with respect to vertebrates, increasing Environ Sci Pollut Res the probability that wild species can be affected under field- several routes of exposure, e.g. from ingestion of treated seed; realistic exposure conditions. from residues in or on the crop and soil; from drinking water, nearby vegetation or invertebrates; from dermal exposure due Are vertebrates at risk in their natural environment? to direct overspray or contact with treated surfaces; from inhalation; and even from preening. Concentrations to which Risks to aquatic vertebrates terrestrial taxa can be exposed vary markedly within and between these different pathways, based on habitat require- Various measured or estimated environmental concentrations ments and movement between contaminated and uncontami- of imidacloprid, clothianidin and fipronil in the aquatic envi- nated patches. ronment are available. For imidiacloprid, these include 0– Treated seeds contain some of the highest concentrations of 0.22 μg/L (Lamers et al. 2011); mean and maximum values neonicotinoids, with a typical individual canola (oilseed rape), of 0.016 and 0.27 μg/L, respectively (Main et al. 2014); 0.13– beet or corn seed calculated to contain 0.17, 0.9 or 1 mg of 0.14 μg/L (Stoughton et al. 2008); 0–3.3 μg/L (Starner and active ingredient, respectively (Goulson 2013). Application Goh 2012); 1–14 μg/L (Jemec et al. 2007); <15 μg/L rates vary widely by crop but, for example, canola seeds (Kreuger et al. 2010); 17–36 μg/L (Fossen 2006); and up to treated with clothianidin have recommended application 49 μg/L (Hayasaka et al. 2012). Higher concentrations of rates of 4.0 g a.i./kg of canola seed, while corn is almost imidacloprid have been more rarely recorded in the aquatic double, at 7.5 g a.i./kg seed. Given these high environment. In one study in the Netherlands, while 98 % of concentrations, and that many granivorous species eat crop 1,465 measurements ranged from 0 to 8.1 μg/L, the remaining seeds, the most likely route of exposure to terrestrial animals is 2 % were up to 320 μg/L (Van Dijk et al. 2013). Similarly, in a probably through the consumption of treated seeds. studyinexperimentalricefields, the concentration of Residues in crops and surrounding soil may be lower but imidacloprid immediately after application was 240 μg/L, still pose a risk to wildlife consumers that feed on the treated but fell to 5 μg/L within a week (Sánchez-Bayo and Goka plants or ingest soil. For example, Bonmatin et al. (2005) 2005). For clothianidin, DeCant and Barrett (2010) estimated found residues of 2.1–6.6 μg/kg of imidacloprid in seed- concentrations of 0.5–3.0 μg/L for standing water surround- treated maize plants. Substantially higher concentrations of ing two crops, while Main et al. (2014) measured mean and 1.0–12.4 mg/kg of imidacloprid have been detected in seed- maximum concentrations of 0.14 and 3.1 μg/L, respectively, treated sugar beet leaves (Rouchaud et al. 1994). Ground- in water bodies beside canola fields. Measurements for dwelling species may also be exposed via the soil. Anon fipronil in the aquatic environment have been reported at (cited in Goulson 2013) found concentrations of 18–60 μg/ 0.17 μg/L (Stark and Vargas 2005); a median of 0.23 and kg of imidacloprid in soil following several years of repeated range of 0.004–6.4 μg/L (Mize et al. 2008); 1 μg/L (Hayasaka applications as a seed treatment on winter wheat. et al. 2012); and 0.15–5 μg/L (Wirth et al. 2004). Donnarumma et al. (2011) measured concentrations of

Imidacloprid LC50 measurements for fish and amphibia 652 μg/kg of imidacloprid in soil 30 days after sowing of (Table 1) range from 1,200 to 366,000 μg/L, and for dressed maize seeds, falling to 11 μg/kg at harvest. Following clothianidin, from 94,000 to 117,000 μg/L (fish only). Thus, soil drenching (i.e. applying a diluted insecticide directly to except in the most extreme cases, environmental concentra- the base of a plant), Cowles et al. (2006) found concentrations tions are from approximately 2 to 7 orders of magnitude lower of 120–220 μg/kg of imidacloprid in hemlock, Tsuga than LC50 measurements for fish and amphibians, so it is Canadensis, tissue. Cutler and Scott-Dupree (2007) found unlikely that the mortality rates of these taxa will be directly residues of 0.5–2.6 μg/kg of clothianidin in seed-treated ca- affected by these two insecticides under normal exposure. nola plants, while Krupke et al. (2012) found residues of 1– However, the possibility of sub-lethal effects, e.g. physiolog- 9 μg/kg of clothianidin on natural vegetation surrounding ical stress and damage to DNA, cannot be ruled out (Table 2). seed-treated maize fields. Krupke et al. (2012)alsodetected For fipronil, there is a greater apparent risk to fish survival, as concentrations of 6.3 μg/kg of clothianidin in soil in fields some of the highest environmental concentrations are within sown with seed-treated maize. an order of magnitude of their LC50 values (Table 1), espe- The US EPA modelled the estimated daily intake of cially for bluegill sunfish and Nile tilapia. Sub-organism ef- clothianidin, assuming that mammals and birds only eat a diet fects may also be apparent, for example, erythrocyte damage of treated seeds (DeCant and Barrett 2010). This risk model- and alterations to gene transcription (Table 2). ling approach showed that clothianidin, at least when used to treat oilseed rape and cotton seeds, could reduce the survival Risks to terrestrial vertebrates of small birds and mammals (DeCant and Barrett 2010). Similar approaches have been developed for other routes of Determining the exposure risks to terrestrial vertebrates is exposure beyond ingestion of seed treatments (e.g. SERA more complex than to aquatic species given that there are 2005;USEPA2012). For example, risk modelling for Environ Sci Pollut Res imidacloprid suggests hazards to birds and mammals consum- (2010), Mineau and Palmer (2013)andGoulson(2013). An- ing vegetation, grass and even insects. In particular, it predicts ecdotal observations of blackbirds and sparrows foraging in that foliar spraying may lead to substantial mortality of sensi- fields recently seeded with neonicotinoid-treated crops sug- tive bird species (SERA 2005). In its 2008 re-assessment of gest that the calculated risks are further plausible (C. imidacloprid, the US EPA (2008)reportedanincidentwhere Morrissey personal observation). grubs surfacing after a lawn treatment appear to have poisoned young robins, Turdus migratorius. A more detailed assessment of the risk of intoxication of birds following the consumption of neonicotinoid-treated seed The indirect effects of pesticides on vertebrate wildlife is given by Mineau and Palmer (2013). Their analysis sug- gests that the risks of acute intoxication with imidacloprid While rarely considered in ecological risk assessments, con- applied on maize, oilseeds or cereals are comparably high, cerns about the impacts of pesticide use on vertebrates have such that birds need only to ingest a few treated seeds. The risk more recently turned to the widespread potential for indirect of acute intoxication with clothianidin in maize is highest, effects (Sotherton and Holland 2002; Boatman et al. 2004). whereas for oilseeds or cereals, birds would need to ingest Observations of farmland and grassland bird declines and more, largely because application rates are lower. In principle, range contractions correlate well with agricultural intensifica- there are ways in which this risk could be mitigated, for tion, including increased pesticide use (Chamberlain et al. example, by burying seeds below the soil surface, but this is 2000;Morrisetal.2005; Ghilain and Bélisle 2008; rarely 100 % effective due to spillage (de Leeuw et al. 1995; Robillard et al. 2013; Mineau and Whiteside 2013). Tennekes Pascual et al. 1999). Whether or not birds avoid eating treated (2010) and Mason et al. (2012) have recently suggested, albeit seeds (Avery et al. 1998), or the extent to which they may with little supporting evidence, that neonicotinoid insecticides remove a substantial proportion of the toxicant by discarding may be contributing to declines of insectivorous birds in outer seed husks (Avery et al. 1997) have been debated. Europe, and of fish, amphibians, bats and birds around the However, incidents of bird poisoning with imidacloprid- world, respectively. Tennekes (2010) hypothesized that treatedseedhavebeendocumented(Bernyetal.1999), sug- neonicotinoids were acting indirectly on bird populations, by gesting that the calculated risk may be real. reducing the abundance of their insect prey. Mason et al. The potential risk to birds from eating neonicotinoid- (2012) suggested that neonicotinoids have suppressed the treated seeds can be illustrated by the following example in immune system of vertebrates (and invertebrates) making which we calculate the relative risk for two granivorous spe- them more prone to infectious disease and other stressors. cies, a grey partridge, Perdix perdix (mass ~390 g) and a house Indirect effects of pesticides on vertebrates are most com- sparrow (mass ~34 g) (http://blx1.bto.org/birdfacts/results/ monly exerted in one of three ways: (1) through reductions of bob3670.htm), feeding on a field recently sown with plant seed food for granivores following herbicide applica- imidacloprid-treated beet seed, each containing 0.9 mg of tions (e.g. Gibbons et al. 2006); (2) through the loss of insect imidacloprid (Anon 2012). Imidacloprid is highly toxic to host plants following herbicide applications and the secondary both species, with a LD50 of 13.9 mg/kg of body weight for impacts for dependent insects and insectivores, (e.g. Potts grey partridge and 41 mg/kg for house sparrow (Table 1). 1986); or (3) through reductions in arthropod prey for insec- Consequently, ingestion of just 6 and 1.5 seeds would have a tivores following applications of insecticides—or fungicides 50 % chance of killing an individual foraging partridge and with insecticidal properties (e.g. Martin et al. 2000;Morris sparrow, respectively. Less than a quarter of a seed could have et al. 2005;Poulinetal.2010). a sub-lethal effect on a house sparrow, as 6 mg/kg is sufficient Indirect effects are inherently difficult to measure and to reduce flying ability (Table 2;Cox2001). While de Leeuw frequently suffer from limitations of correlative inferences. et al. (1995) suggest that only 0.17 % of beet seeds remain on Boatman et al. (2004) highlighted three criteria for conclu- the soil surface after sowing, at a maximum drilling rate of sively inferring a causal link between pesticides and their 130,000 seeds per hectare (Anon 2012), 6 and 1.5 seeds would indirect actions on vertebrate wildlife. Conclusive studies be found on the surface in areas of approximately 270 and should document negative effects on (1) food quality and 70 m2, respectively, well within the daily foraging ranges of quantity, (2) reproduction, condition or survivorship of the each species. Areas of accidentally spilled seed could contain vertebrate consumer and (3) concomitant vertebrate popula- much higher densities. While individual partridges and spar- tion declines. The only documented case where indirect ef- rows may not ingest treated seeds (i.e. as the brightly coloured fects were definitively shown using the full range of these seed coatings may deter birds if they represent a novel food criteria in a fully replicated field experiment was for the grey source), these calculations suggest that there is a potential risk partridge in Britain (Rands 1985) following several decades of of imidacloprid-treated seeds to affect sensitive bird species, intensive study. Population modelling showed that declines in consistent with conclusions drawn by DeCant and Barrett grey partridge populations could be wholly explained by Environ Sci Pollut Res herbicide-induced reductions in prey availability in tandem (Table 3). All were field rather than laboratory-based studies. with reduced growth and survival of grey partridge chicks Of these studies, one found a beneficial, indirect effect. Fe- (reviewed by Potts 1986). Other studies, however, have re- male Cape ground squirrels, Xerus inauris, benefited from vealed consistent effects on one or more of these three criteria, ectoparasite removal with fipronil and had fourfold higher suggesting that the indirect effects of pesticides may be more breeding success (Hillegass et al. 2010). A number of studies prevalent than documented in the literature. have shown that reducing parasite burdens can enhance ver- tebrate breeding success (e.g. Hudson et al. 1992). However, Studies reporting effects on consumers through food interpretation of the effect of fipronil was not straightforward, reductions as endoparasites were simultaneously removed with ivermec- tin, and researchers could not distinguish the effects of the two Pesticide applications, in temperate regions, directly overlap products. with the seasonal production of invertebrates and the breeding In two further field studies, both in experimental rice fields, seasons of a range of numerous vertebrate species. Food imidacloprid and/or fipronil was applied at the recommended supply (i.e. abundance and availability) is widely accepted commercial rates. While one study found no effect of fipronil as affecting habitat selection, reproductive success and sur- on growth or survival of Japanese carp, Cyprinus carpio vival in vertebrates, with extensive supporting evidence for (Clasen et al. 2012), the other found that both imidacloprid birds in particular (Simons and Martin 1990; Johansson and and fipronil applications reduced the growth of both adult and Blomqvist 1996; Brickle et al. 2000;Moller2001;Holeetal. fry medaka fish, Oryzias latipes (Hayasaka et al. 2012). 2002; Nagy and Holmes 2004, 2005; Boatman et al. 2004; Hayasaka et al. (2012) suggest that this is most likely an Morris et al. 2005; Britschgi et al. 2006;Hartetal.2006; indirect effect, through a reduction in the abundance of me- Zanette et al. 2006; Golawski and Meissner 2008; Selås et al. daka prey. The concentrations were probably too low (approx- 2008;Dunnetal.2010; Poulin et al. 2010). Across Europe imately 0.001 to 0.05 mg/L) to exert a direct toxic effect on and North America, dramatic and widespread declines have medaka but assumed sufficiently high to reduce the abun- been observed in populations of birds associated with farm- dance of their invertebrate prey. land and wetland habitats (Beauchamp et al. 1996;Donald Population-level studies investigating indirect impacts of et al. 2001;Bentonetal.2002; Boatman et al. 2004), with neonicotinoids and fipronil on vertebrate species are rare. arthropod abundance showing similar trends (Benton et al. Only three such studies were found during this review, and 2002). In Canada and the USA, however, species loss has all were of local—rather than national or regional—popula- been more strongly correlated with pesticide use than agricul- tions (Table 3). All were field studies that applied either tural area or intensification measures alone (Gibbs et al. 2009; imidacloprid or fipronil at recommended commercial rates Mineau and Whiteside 2013). using sprays or soil drenching, rather than seed treatments. Reductions in invertebrate food abundance caused by in- Falcone and DeWald (2010) investigated the impact of a secticide use has been linked to reductions in reproductive single soil drenching application with imidacloprid on eastern success of at least four farmland passerines in the UK: corn hemlock, Tsuga Canadensis, as part of a campaign to reduce bunting, Miliaria calandra, yellowhammer, Emberiza numbers of an exotic insect pest. While the soil drenching had citrinella, whinchat, Saxicola rubetra, and reed bunting, (surprisingly) no impact on the woolly adelgid (Adelges Emberiza schoeniclus (Brickle et al. 2000; Brickle and tsugae) pest, populations of non-target hemiptera and Peach 2004;Morrisetal.2005;Hartetal.2006;Dunnetal. lepidoptera were reduced. Despite lepidopteran larvae being 2010; but see Bradbury et al. 2000, 2003). Although declines important in the diet of three neotropical migrant in bird populations in the UK have been coincident with insectivorous bird species, bird numbers were not affected in invertebrate losses, changes in invertebrate abundance alone the following year. Norelius and Lockwood (1999) undertook do not fully explain population trends for these species. In a similar study, this time spraying with fipronil to control a fact, the nesting success of these species increased during time grasshopper outbreak. While grasshopper numbers were periods when populations were declining (Siriwardena et al. markedly reduced, populations of insectivorous prairie birds 2000). Population declines of seed eaters have instead been that commonly consume the grasshoppers were slightly, but linked to reduced over-winter survival, likely as a conse- not significantly, reduced a month after spraying. The lack of quence of reduced seed availability (Siriwardena et al. 2000; clear population-level effects in both these studies may have Butler et al. 2010). been related to birds seeking food outside treated areas in compensation, although this seems unlikely, at least for the Indirect effects of neonicotinoids and fipronil Norelius and Lockwood (1999) study, as the home ranges of the birds studied (few hectares) were small compared to the We found only six studies that have investigated the indirect total treated area (few hundred hectares). Alternatively, effects of neonicotinoids and fipronil on vertebrate wildlife population-level effects could have been masked in such Environ Sci Pollut Res

Table 3 Indirect effects of imidacloprid and fipronil on vertebrates

Taxon and Species Effect on: Imidacloprid Fipronil Source and detailed effect

Mammal Lesser hedgehog tenrec, Population REC Peveling et al. 2003; marked reduction Echinops telfairi in harvester termite prey may eventually lead to tenrec decline Cape ground squirrel, Xerus Reproduction 0.7 mg/kg; REC Hillegass et al. 2010; removal of ectoparasites inauris (POS) (with fipronil) and endoparasites boosted breeding success; unable to determine impact of fipronil alone Bird 3 neotropical migrant Population REC (NE) Falcone and DeWald 2010; spraying reduced insectivores lepidopteran prey, but not populations of black- throated green warbler (Dendroica virens), black-throated blue warbler (D. caerulescens) and blue-headed vireo (Vireo solitarius) 38 species, of which 33 were Population REC (NE) Norelius and Lockwood 1999; marked reduction insectivores in grasshoppers, but not in bird densities; 34 bird species studied, most abundant were horned lark, Eremophila alpestris, western meadowlark, Sturnella neglecta, and lark sparrow, Chondestes grammacus Fish Medaka, Oryzias latipes Growth & 0.001 mg/L; 0.001–0.05 mg/L; Hayasaka et al. 2012; reduced growth of development REC REC both adults and fry Japanese carp, Cyprinus carpus Growth and survival REC (NE) Clasen et al. 2012;noeffectongrowthand survival of Japanese carp Reptile Madagascar iguana, Population REC7 Peveling et al. 2003; marked reduction in Chalarodon harvester termite prey led to decline in madagascariensis iguana population Askink,Mabuy elegans Population REC7 Peveling et al. 2003; marked reduction in harvester termite prey led to decline in skink population

All other studies demonstrated deleterious effects REC insecticide applied at manufacturer’s recommended rate, NE no effect at the given dosage, POS positive effect at the given dosage relatively small-scale field trials if birds had immigrated into population-level impact of a systemic insecticide on a verte- the treated plots from surrounding un-treated areas. Neither brate population, where its effect was exerted indirectly study, however, measured breeding success or impacts on through the food chain. While Tingle et al. (2003)reportthat chick survival which may be more plausible than effects on a study of fipronil spraying to control locusts in Madagascar adult survival. may have caused population declines of two bird species, In contrast, Peveling et al. (2003) documented how fipronil Madagascar bee-eater, Merops superciliosus, and Madagascar spraying to control a plague of migratory locusts in Madagas- kestrel, Falco newtoni, (but no effect on two others, Mada- car halved populations of the harvester termite, Coarctotermes gascar bush lark, Mirafra hova, and Madagascar cisticola, clepsydra. Consequently, populations of two lizard species, Cisticola cherina), sample sizes were too small to be conclu- the Madagascar iguana, Chalarodon madagascariensis,anda sive, and it was not possible to distinguish between direct and skink, Mabuy elegans, declined, because termites form an indirect effects. important part of the diet of both species, while the lesser While it is possible to use laboratory toxicity studies to hedgehog tenrec, Echinops telfairi, may have also been af- inform models on the indirect effects of a pesticide on verte- fected. To date, this is the only study that has demonstrated a brate populations, such models are very data-demanding and Environ Sci Pollut Res case studies are rare (see e.g. Watkinson et al. 2000). Systemic Stiftung Landwirtschaft (Germany), Study Association Storm (Student insecticides are known to affect invertebrate populations (e.g. Association Environmental Sciences Utrecht University) and citizens. The funders had no role in study design, data collection and analysis, Whitehorn et al. 2012; Van Dijk et al. 2013), but the lack of decision to publish, or preparation of the manuscript, and none of the evidence for, and difficulty in determining, comparable indi- authors received funding from any of these sources. The authors declare rect effects on vertebrates is an issue in ecotoxicology. There no conflicts of interest. remains an essential need to determine if a causal link between Open Access This article is distributed under the terms of the Creative loss of insect prey through pesticide use and the decline of Commons Attribution License which permits any use, distribution, and vertebrate populations exists. This is especially true in North reproduction in any medium, provided the original author(s) and the America and Europe where neonicotinoids are being used in source are credited. large quantities and over vast areas.

References Conclusions Abou-Donia MB, Goldstein LB, Bullman S, Tu T, Khan WA, Neonicotinoid and fipronil insecticides can exert their impact Dechkovskaia AM, Abdel-Rahman AA (2008) Imidacloprid in- on vertebrates either directly, through their overt toxicity, or duces neurobehavioral deficits and increases expression of glial indirectly, for example, by reducing their food supply. Marked fibrillary acidic protein in the motor cortex and hippocampus in offspring rats following in utero exposure. J Toxicol Environ Health variation exists among taxa and different systemic insecticides A71:119–130 in acute toxicity (as measured by LD50 and LC50), while a Anon (2012) Addendum 7 to the draft assessment report; confirmatory range of sub-lethal effects can occur at concentrations orders data; imidacloprid. EU Commission of magnitude below those causing lethality. Overall, at con- Avery ML, Fischer DL, Primus TM (1997) Assessing the hazard to granivorous birds feeding on chemically treated seeds. Pestic Sci centrations relevant to field exposure scenarios from seed 49:362–366 treatments (birds) or water concentrations (fish), imidacloprid Avery ML, Primus TM, Mihaich EM, Decker DG, Humphrey JS (1998) and clothianidin can be considered a risk to granivorous bird Consumption of fipronil-treated rice seed does not affect captive – species, while fipronil may pose a similar risk to sensitive fish blackbirds. Pest Manag Sci 52:91 96 Badgujar PC, Jain SK, Singh A, Punia JS, Gupta RP, Chandratre GA species. Except in the most extreme cases, however, concen- (2013) Immunotoxic effects of imidacloprid following 28 days of trations of imidacloprid and clothianidin that fish and amphib- oral exposure in BALB/c mice. Environ Toxicol Pharmacol 35:408– ians are exposed to appear to be substantially below thresholds 418 ı ğ ş ğ to cause mortality, although sub-lethal effects have not been Bal R, Türk G, Y lmaz Ö, Etem E, Kulo lu T, Bayda G, Naziro lu M (2012) Effects of clothianidin exposure on sperm quality, testicular widely studied. apoptosis and fatty acid composition in developing male rats. Cell Despite the lack of research and the difficulty in assigning Biol Toxicol 28:187–200 causation, indirect effects may be as—or even more—impor- Bal R, Türk G, Tuzcu M, Yılmaz Ö, Kuloğlu T, Baydaş G, Naziroğlu M, tant than direct toxic effects on vertebrates, as modern sys- Yener Z, Etem E, Tuzcu Z (2013) Effects of the neonicotinoid insecticide, clothianidin, on the reproductive organ system in adult temic insecticides are more effective at killing the invertebrate male rats. Drug Chem Toxicol 36:421–429 prey of vertebrates than the vertebrates themselves. Given the Beauchamp WD, Koford RR, Nudds TD, Clark RG, Johnson DH (1996) data here, current risk assessment procedures for Long-term declines in nest success of prairie ducks. J Wildl Manag – neonicotinoids and other systemic pesticides need to consider 60:247 257 Beggel S, Werner I, Connon RE, Geist JP (2010) Sublethal toxicity of the associated risks from both direct and indirect effects to commercial insecticide formulations and their active ingredients to vertebrate wildlife. larval fathead minnow (Pimephales promelas). Sci Total Environ 408(16):3169–3175 Acknowledgments This manuscript benefited from discussions in the Beggel S, Werner I, Connon RE, Geist JP (2012) Impacts of the International Task Force on Systemic Pesticides (TFSP) during its plenary phenylpyrazole insecticide fipronil on larval fish: time-series meetings in Paris (2010), Bath (2011), Cambridge (2012), Padua (2012), gene transcription responses in fathead minnow (Pimephales Louvain-la-Neuve (2013) and Legnaro (2013). We thank the members of promelas) following short-term exposure. Sci Total Environ the TFSP for their advice and encouragement, particularly Dominique 426:160–165 Noome, Maarten Bijleveld van Lexmond, Jeroen van der Sluijs, Noa Benton TG, Bryant DN, Cole L, Crick HQP (2002) Linking agricultural Simon Delso and Jean-Marc Bonmatin. We also thank Brigitte Poulin and practice to insect and bird populations: a historical study over three Barnett Rattner for generously providing a critical review of an earlier decades. J Appl Ecol 39:673–687 version of the manuscript. The work of the TFSP was funded by Triodos Berny PJ, Buronfosse F, Videmann B, Buronfosse T (1999) Evaluation of Foundation’s ‘Support Fund for Independent Research on Bee Decline the toxicity of imidacloprid in wild birds. A new high performance and Systemic Pesticides’. This Support Fund was created from donations thin layer chromatography (HPTLC) method for the analysis of liver by Adessium Foundation (The Netherlands), Act Beyond Trust (Japan), and crop samples in suspected poisoning cases. J Liq Chrom Rel Universiteit Utrecht (Netherlands), Stichting Triodos Foundation (The Technol 22:1547–1559 Netherlands), Gesellschaft fuer Schmetterlingsschutz (Germany), Bhardwaj S, Srivastava MK, Kapoor U, Srivastava LP (2010) A 90 days M.A.O.C. Gravin van Bylandt Stichting (The Netherlands), Zukunft oral toxicity of imidacloprid in female rats: morphological, Environ Sci Pollut Res

biochemical and histopathological evaluations. Food Chem Toxicol cultured human lymphocytes and rat bone-marrow. Mutat Res 634: 48:1185–1190 32–39 Boatman ND, Brickle NW, Hart JD, Milsom TP, Morris AJ, Murray Donald PF, Green RE, Heath MF (2001) Agricultural intensification and AWA, Murray KA, Pobertson PA (2004) Evidence for the indirect the collapse of Europe’s farmland bird populations. Proc R Soc B effects of pesticides on farmland birds. Ibis 146:131–143 268:25–29 Bonmatin JM, Marchand PA, Charvet R, Moineau I, Bengsch ER, Colin Donnarumma L, Pulcini P, Pochi D, Rosati S, Lusco L, Conte E (2011) ME (2005) Quantification of imidacloprid uptake in maize crops. J Preliminary study of persistence in soil and residues in maize of Agric Food Chem 53:5336–5341 imidacloprid. J Environ Sci Health B 46:469–472 Bradbury RB, Kyrkos A, Morris AJ, Clark SC, Perkins AJ, Wilson JD Dunn JC, Hamer KC, Benton TG (2010) Fear for the family has negative (2000) Habitat associations and breeding success of yellowhammers consequences: indirect effects of nest predators on chick growth in a on lowland farmland. J Appl Ecol 37:789–805 farmland bird. J Appl Ecol 47:994–1002 Bradbury RB, Wilson JD, Moorcroft D, Morris A, Perkins AJ (2003) Duzguner V,Erdogan S (2012) Chronic exposure to imidacloprid induces Habitat and weather are weak correlates of nestling condition and inflammation and oxidative stress in the liver and central nervous growth rates of four UK farmland passerines. Ibis 145:295–306 system of rats. Pestic Biochem Physiol 104:58–64 Brickle NW, Peach WJ (2004) The breeding ecology of Reed Buntings European Commission (2005) Clothianidin. SANCO/10533/05—Final, Emberiza schoeniclus in farmland and wetland habitats in lowland 26 pp England. Ibis 146:69–77 Falcone JF, DeWald LE (2010) Comparisons of arthropod and avian Brickle NW, Harper DGC, Aebischer NJ, Cockayne SH (2000) Effects of assemblages in insecticide-treated and untreated eastern hemlock agricultural intensification on the breeding success of corn buntings (Tsuga canadensis [L.] Carr) stands in Great Smoky Mountains Miliaria calandra. J Appl Ecol 37:742–755 National Park, USA. For Ecol Manag 260:856–863 Britschgi A, Spaar R, Arlettaz R (2006) Impact of grassland farming Feng S, Kong Z, Wang X, Zhao L, Peng P (2004) Acute toxicity and intensification on the breeding ecology of an indicator insectivorous genotoxicity of two novel pesticides on amphibian, Rana N passerine, the Whinchat Saxicola rubetra: Lessons for overall Hallowell. Chemosphere 56:457–463 Alpine meadowland management. Biol Conserv 130:193–205 Fossen M (2006) Environmental fate of imidacloprid. Department of Butler SJ, Mattison EHA, Glithero NJ, Robinson LJ, Atkinson PW, Pesticide Regulation, Sacramento Gillings S, Vickery JA, Norris K (2010) Resource availability and Garthwaite DG, Thomas MR, Dawson A, Stoddart H (2003) Pesticide the persistence of seed-eating bird populations in agricultural land- Usage Survey Report 187: arable crops in Great Britain 2002. scapes : a mechanistic modelling approach. J Appl Ecol 47:67–75 Department for Environment, Food and Rural Affairs, London Callahan J, Mineau P (2008) Evaluation of clinical sign data from avian Gawade L, Dadarkar SS, Husain R, Gatne M (2013) A detailed study of acute oral toxicity studies. Appendix 11; Scientific opinion of the developmental immunotoxicity of imidacloprid in Wistar rats. Food panel on plant protection products and their residues on risk assess- Chem Toxicol 51:61–70 ment for birds and mammals. EFSA J 734, 10pp Ghilain A, Bélisle M (2008) Breeding success of tree swallows along a Casida JE, Durkin KA (2013) Neuroactive insecticides: targets, selectiv- gradient of agricultural intensification. Ecol Appl 18:1140–1154 ity, resistance, and secondary effects. Annu Rev Entomol 58:99–117 Ghisi D d C, Ramsdorf WA, Vinícius M, Ferraro M, Almeida MIM, Chamberlain DE, Fuller RJ, Bunce RGH, Duckworth JC, Shrubb M Ribeiro CA d O, Cestari MM (2011) Evaluation of genotoxicity in (2000) Changes in the abundance of farmland birds in relation to Rhamdia quelen (Pisces, Siluriformes) after sub-chronic contamina- the timing of agricultural intensification in England and Wales. J tion with Fipronil. Environ Monit Assess 180:589–599 Appl Ecol 37:771–788 Gibbons DW, Bohan DA, Rothery P, Stuart RC, Haughton AJ, Scott RJ, Clasen B, Loro VL, Cattaneo R, Moraes B, Lópes T, de Avila LA, Zanella R, Wilson JD, Perry JN, Clark SJ, Dawson RJG, Firbank L (2006) Reimche GB, Baldisserotto B (2012) Effects of the commercial formu- Weed seed resources for birds in fields with contrasting conventional lation containing fipronil on the non-target organism Cyprinus carpio: and genetically modified herbicide-tolerant crops. Proc R Soc B Implications for rice-fish cultivation. Ecotoxicol Environ Saf 77:45–51 273:1921–1928 Connelly P (2011) Environmental fate of fipronil. Californian Gibbs KE, Mackey RL, Currie DJ (2009) Human land use, agriculture, Environmental Protection Agency, Sacramento pesticides and losses of imperiled species. Divers Distrib 15:242– Cowles RS, Montgomery ME, Cheah CAS-J (2006) Activity and resi- 253 dues of imidacloprid applied to soil and tree trunks to control Golawski A, Meissner W (2008) The influence of territory characteristics Hemlock Wooly Adelgid (Hemiptera: Adelgidae) in Forests. J and food supply on the breeding performance of the Red-backed Econ Entomol 99:1258–1267 Shrike (Lanius collurio) in an extensively farmed region of eastern Cox C (2001) Insecticide factsheet: imidacloprid. J Pestic Reform 21:15– Poland. Ecol Res 23:347–353 21 Goulson D (2013) An overview of the environmental risks posed by Cutler GC, Scott-Dupree CD (2007) Exposure to clothianidin seed- neonicotinoid insecticides. J Appl Ecol 50:977–987 treated canola has no long-term impact on honey bees. J Econ Grant DB, Chalmers AE, Wolff MA, Hoffman HB, Bushey DF, Kuhr RJ, Entomol 100:765–772 Motoyama N (1998) Fipronil: action at the GABA receptor. In: Kuhr de Leeuw J, Gorree M, de Snoo GR, Jamis WLM, van der Poll RJ, Luttik RJ, Motoyama N (eds) Pesticides and the Future: minimizing chron- R (1995) Risks of granules of treated seeds to birds on arable fields. ic exposure of humans and the environment. IOS Press, Amsterdam, GML report no. 118. Centre of Environmental Science, Leiden pp 147–156 University, Leiden, ISSN 1381–1703 Gu YH, Li Y,Huang XF, Zheng JF, Yang J, Diao H, Yuan Y,Xu Y,Liu M, de Oliveira IM, Nunes BV, Barbosa DR, Pallares AM, Faro LR (2010) Shi HJ, Xu WP (2013) Reproductive effects of two neonicotinoid Effects of the neonicotinoids thiamethoxam and clothianidin on insecticides on mouse sperm function and early embryonic devel- in vivo dopamine release in rat striatum. Toxicol Lett 192:294–297 opment in vitro. PLoS ONE e70111 DeCant J, Barrett M (2010) Environmental fate and ecological risk Hart JD, Milsom TP, Fisher G, Wilkins V, Moreby SJ, Murray AWA, assessment for the registration of clothianidin for use as a seed Robertson PA (2006) The relationship between yellowhammer treatment on mustard seed (oilseed and condiment) and cotton. breeding performance, arthropod abundance and insecticide appli- United States Environmental Protection Agency, Washington cations on arable farmland. J Appl Ecol 43:81–91 Demsia G, Vlastos D, Goumenou M, Matthopoulos DP (2007) Hayasaka D, Korenaga T, Suzuki K, Saito F, Sanchez-Bayo F, Goka K Assessment of the genotoxicity of imidacloprid and metalaxyl in (2012) Cumulative ecological impacts of two successive annual Environ Sci Pollut Res

treatments of imidacloprid and fipronil on aquatic communities of Lopez-Antia A, Ortiz-Santaliestra ME, Mougeot F, Mateo R (2013) paddy mesocosms. Ecotoxicol Environ Saf 80:355–362 Experimental exposure of red-legged partridges (Alectoris rufa)to Hillegass MA, Waterman JM, Roth JD (2010) Parasite removal increases seeds coated with imidacloprid, thiram and difenoconazole. reproductive success in a social African ground squirrel. Behav Ecol Ecotoxicol 22:125–138. doi:10.1007/s10646-012-1009-x 21:696–700 Main AR, Headley JV, Peru KM, Michel NL, Cessna AJ, Morrisey CA Hole DG, Whittingham MJ, Bradbury RB, Anderson GQA, Lee PLM, (2014) Widespread use and frequent detection of neonicotinoid Wilson JD, Krebs JR (2002) Widespread local house-sparrow ex- insecticides in wetlands of Canada’s Prairie Pothole Region. PLoS tinctions. Nature 418:931–932 ONE 9:e92821 Howard JH, Julian SE, Ferrigan J (2003) Golf course maintenance: Martin PA, Johnson DL, Forsyth DJ, Hill BD (2000) Effects of two impact of pesticides on amphibians. Golf Course Mon, September grasshopper control insecticides on food resources and reproductive 94–101 success of two species of grassland songbirds. Environ Toxicol Hudson PJ, Newborn D, Dobson AP (1992) Regulation and stability of a Chem 19:2987–2996 free-living host-parasite system: Trichostrongylus tenuis in red Martins AP (2009) Neurobehavioural effects of acute fipronil adminis- grouse. 1. Monitoring and parasite reduction experiments. J Anim tration in rats. PhD thesis, Faculdade de Medicina Veterinária e Ecol 61:477–486 Zootecnia, Universidade de São Paulo Jemec A, Tišler T, Drobne D, Sepčic’ K, Fournier D, Trebše P (2007) Mason R, Tennekes H, Sánchez-Bayo F, Jepsen PU (2012) Immune Comparative toxicity of imidacloprid, of its commercial liquid for- suppression by neonicotinoid insecticides at the root of global mulation and of diazinon to a non-target arthropod, the wildlife declines. J Environ Immunol Toxicol 1:3–12 microcrustacean Daphnia magna. Chemosphere 68:1408–1418 Mineau P (2005) A review and analysis of study endpoints relevant to the Jeschke P, Nauen R (2008) Neonicotinoids—fromzerotoheroininsec- assessment of ‘long term’ pesticide toxicity in avian and mammalian ticide chemistry. Pest Manag Sci 64:1084–1098 wildlife. Ecotoxicol 14:775–799 Jeschke P, Nauen R, Schindler M, Elbert A (2011) Overview of the status and Mineau P (2011) Barking up the wrong perch: why we should stop global strategy for neonicotinoids. J Agric Food Chem 59:2897–2908 ignoring non-dietary routes of pesticide exposure in birds. Integr Johansson OC, Blomqvist D (1996) Habitat selection and diet of lapwing, Environ Assess Manag 7:297–305 Vanellus vanellus, chicks on coastal farmland in SW Sweden. J Appl Mineau P, Palmer C (2013) The impact of the nation’smostwidelyused Ecol 33:1030–1040 insecticides on birds. American Bird Conservancy, USA Kapoor U, Srivastava MK, Bhardwaj S, Srivastava LP (2010) Effect of Mineau P, Whiteside M (2013) Pesticide acute toxicity is a better correlate imicacloprid on antioxidant enzymes and lipid peroxidation in fe- of U.S. grassland bird declines than agricultural intensification. male rats to derive its No Observed Effect Level (NOEL). J Toxicol PLoS ONE 8:e57457 Sci 35:577–581 Mineau P, Boersma DC, Collins B (1994) An analysis of avian repro- Kaur B, Sandhu HS, Kaur R (2006) Toxic effects of subacute oral duction studies submitted for pesticide registration. Ecotoxicol exposure of imidacloprid on biochemical parameters in crossbred Environ Saf 29:304–329 cow calves. Toxicol Int 13:43–47 Mineau P, Balcomb R, Bennett R, Dobson S, Fry M, Jaber M, Leopold A, Kitulagodage M, Astheimer LB, Buttemer WA (2008) Diacetone alcohol, Munk R, Ringer B, Rispin A, Sileo L, Solecki R, Thompson H (1996) a dispersant solvent, contributes to acute toxicity of a fipronil-based Testing for effects on reproduction. In: Report of the SETAC/OECD insecticide in a passerine bird. Ecotoxicol Environ Saf 71:597–600 Workshop on Avian Toxicity Testing. Inter-Organizational Programme Kitulagodage M, Buttemer WA, Astheimer LB (2011a) Adverse effects for the Sound Management of Chemicals, OECD Environmental of fipronil on avian reproduction and development: maternal transfer Health and Safety Publications, Series on Testing and Assessment No. of fipronil to eggs in zebra finch Taeniopygia guttata and in ovo 5, pp 44–62 exposure in chickens Gallus domesticus. Ecotoxicol 20:653–660 Mineau P, Fletcher MR, Glaser LC, Thomas NJ, Brassard C, Wilson LC, Kitulagodage M, Isanhart J, Buttemer WA, Hooper MJ, Astheimer LB Elliott JE, Lyon LA, Henny CJ, Bollinger T, Porter SL (1999) (2011b) Fipronil toxicity in northern bobwhite quail Colinus Poisoning of raptors with organophosphorous and carbamate pesti- virginianus: reduced feeding behaviour and sulfone metabolite for- cides with emphasis on Canada, the United States and the United mation. Chemosphere 83:524–530 Kingdom. J Raptor Res 33:1–37 Köhler H-R, Triebskorn R (2013) Wildlife ecotoxicology of pesticides: can Mize SV, Porter SD, Demcheck DK (2008) Influence of fipronil com- we track effects to the population level and beyond. Science 341:759– pounds and rice cultivation land-use intensity on macro-invertebrate 765 communities in streams of southwestern Louisiana, USA. Environ Kreuger J, Graaf S, Patring J, Adieslsson S (2010) Pesticides in surface Pollut 152:491–503 water in areas with open ground and greenhouse horticultural crops Mohany M, Badr G, Refaat I, El-Feki M (2011) Immunological and in Sweden, 2008. Swedish University of Agricultural Science. http:// histological effects of exposure to imidacloprid insecticide in male www-mv.slu.se/webfiles/vv/CKB/Ekohydrologi_117_ENG.pdf. albino rats. Afr J Pharm Pharmacol 5:2106–2114 Accessed 4 Feb 2013 Moller AP (2001) The effect of dairy farming on barn swallow Hirundo Krupke CH, Hunt GJ, Eitzer BD, Andino G, Given K (2012) Multiple rustica abundance, distribution and reproduction. J Appl Ecol 38: routes of pesticide exposure for honey bees living near agricultural 378–389 fields. PLoS ONE 7:e29268. doi:10.1371/journal.pone.0029268 Morris AJ, Wilson JD, Whittingham MJ, Bradbury RB (2005) Indirect Lamers M, Anyusheva M, La N, Nguten V, Streck T (2011) Pesticide effects of pesticides on breeding yellowhammer (Emberiza pollution in surface and groundwater by paddy rice cultivation: a case citrinella). Agric Ecosyst Environ 106:1–16 study from Northern Vietnam. Clean Soil Air Water 39:356–361 Nagy LR, Holmes RT (2004) Factors influencing fecundity in migratory Lauan MCB, Ocampo PP (2013) Low-dose effects of carbaryl, chlorpyr- songbirds: is nest predation the most important? J Avian Biol 35: ifos and imidacloprid on the gonad and plasma testosterone level of 487–491 male juvenile and adult Nile tilapia (Oreochromis niloticus Nagy LR, Holmes RT (2005) Food limits annual fecundity of a migratory Linnaeus). Asia Life Sci 1:239–250 songbird: an experimental study. Ecol 86:675–681 Leghait J, Gayrard V, Toutain P-L, Picard-Hagen N, Viguié C (2010) Is Nellore K, Raj K, Usha Rani CT, Jacob DP (2010) Studies on the effect of the mechanism of fipronil-induced thyroid disruption specific to the imidacloprid toxicity on the acetylcholine esterase activity levels in rat: re-evaluation of fipronil thyroid toxicity in sheep? Toxicol Lett different regions of the brain of the albino rat. Int J Agric Environ 194:351–357 Biotechnol 3:377–380 Environ Sci Pollut Res

Newton I (1995) The contribution of some recent research on birds to Stark JD, Vargas RI (2005) Toxicity and hazard assessment of fipronil to ecological understanding. J Anim Ecol 64:675–695 Daphnia Pulex. Ecotoxicol Environ Saf 62:11–16 Nian Y (2009) Study on toxicity of triazophos, trichlorphon and imidacloprid Starner K, Goh KS (2012) Detections of the neonicotinoid insecticide on Rana limnocharis tadpole. J Anhui Agric Sci 2009:18 imidacloprid in surface waters of three agricultural regions of Norelius EE, Lockwood JA (1999) The effects of reduced agent-area California, USA, 2010–2011. Bull Environ Contam Toxicol 88: insecticide treatments for rangeland grasshopper (Orthoptera: 316–321 Acrididae) control on bird densities. Arch Environ Contam Stehr CM, Linbo TL, Incardona JP, Scholz NL (2006) The developmental Toxicol 37:519–528 neurotoxicity of fipronil: notochord degeneration and locomotor Ocampo PP, Sagun VG (2007) Gonadal changes in male tilapia defects in zebrafish embryos and larvae. Toxicol Sci 92:270–278 (Oreochromis niloticus Linn.) after exposure to imidacloprid insec- Stoughton SJ, Liber K, Culp J, Cessna A (2008) Acute and chronic ticide. Phillipine Entomol 21:199–200 toxicity of imidacloprid to the aquatic invertebrates Chironomus Ohi M, Dalsenter PR, Andrade AJM, Nascimento AJ (2004) tentans and Hyalella azteca under constant- and pulse-exposure Reproductive adverse effects of fipronil in Wistar rats. Toxicol Lett conditions. Archives Environ Contam Toxicol 54:662–673 146:121–127 Suryanarayanan S (2013) Balancing control and complexity in field Pascual JA, Hart ADM, Saunders PJ, McKay HV, Kilpatrick J, Prosser P studies of neonicotinoids and honey bee health. Insects 4:153–167 (1999) Agricultural methods to reduce the risk to birds from cereal Tanaka T (2012) Reproductive and neurobehavioral effects of seed treatments on fenlands in eastern England. I. Sowing depth. clothianidin administered to mice in the diet. Birth Defects Res B Agric Ecosyst Environ 72:59–73 95:151–159. doi:10.1002/bdrb.20349 Peveling R, Demba SA (2003) Toxicity and pathogenicity of Metarhizium Tennekes H (2010) The systemic insecticides: a disaster in the making. anisopliae var. acridum (Deuteromycotina, Hyphomycetes) and fipronil ETS Nederland BV, Zutphen, The Netherlands to the fringe-toed lizard Acanthodactylus dumerili (Squamata: Terçariol PRG, Godinho AF (2011) Behavioural effects of acute exposure Lacertidae). Environ Toxicol Chem 22:1437–1447 to the insecticide fipronil. Pestic Biochem Physiol 99:221–225 Peveling R, McWilliam AN, Nagel P, Rasolomanana H, Raholijaona, Tingle CCD, Rother JA, Dewhurst CF, Lauer S, King WJ (2000) Health Rakotomianina L, Ravoninjatovo A, Dewhurst CF, Gibson G, and environmental effects of fipronil. Briefing paper for Pesticides Rafanomezana S, Tingle CCD (2003) Impact of locust control on Action Network, UK harvester termites and endemic vertebrate predators in Madagascar. J Tingle CCD, Rother JA, Dewhurst CF, Lauer S, King WJ (2003) Fipronil: Appl Ecol 40:729–741 environmental fate, ecotoxicology and human health concerns. Rev Potts GR (1986) The partridge—pesticides, predation and conservation. Environ Contam Toxicol 176:1–66 Collins, London Tišler T, Jemec A, Mozetič B, Trebše P (2009) Hazard identification of Poulin B, Lefebvre G, Paz L (2010) Red flag for green spray: adverse imidacloprid to aquatic environment. Chemosphere 76:907–914 trophic effects of Bti on breeding birds. J Appl Ecol 47:884–889 Tokumoto J, Danjo M, Kobayashi Y, Kinoshita K, Omotehara T, Tatsumi A, Prosser P, Hart ADM (2005) Assessing potential exposure of birds to Hashiguchi M, Sekijima T, Kamisoyama H, Yokoyama T, Kitagawa H, pesticide-treated seeds. Ecotoxicol 14:679–691 Hoshi N (2013) Effects of exposure to clothianidin on the reproductive Rands MRW (1985) Pesticide use on cereals and the survival of grey system of male quails. J Vet Med Sci 75:755–760 partridge chicks: a field experiment. J Appl Ecol 22:49–54 Tomizawa M, Casida JE (2005) Neonicotinoid insecticide toxicology: Ratcliffe DA (1967) Decrease in eggshell weight in certain birds of prey. mechanisms of selective action. Annu Rev Pharmacol Toxicol 45: Nature 215:208–210 247–268 Robillard A, Garant D, Bélisle M (2013) The swallow and the sparrow: Tomizawa M, Casida JF (2011) Neonicotinoid insecticides: highlights of how agricultural intensification affects abundance, nest site selection a Symposium on Strategic Molecular Designs. J Agric Food Chem and competitive interactions. Landsc Ecol 28:201–215 59:2883–2886 Rouchaud J, Gustin F, Wauters A (1994) Soil biodegradation and leaf Toor HK, Sangha GK, Khera KS (2013) Imidacloprid induced histolog- transfer of insecticide imidacloprid applied in seed dressing in sugar ical and biochemical alterations in liver of female albino rats. Pestic beet crops. Bull Environ Contam Toxicol 53:344–350 Biochem Physiol 105:1–4 Sánchez-Bayo F (2011) Impacts of agricultural pesticides on terrestrial US EPA (2008) Imidacloprid summary document registration review: ecosystems. In: Sánchez-Bayo F (ed) Ecological impacts of toxic initial docket December 2008. Docket Number: EPA-HQ-OPP- chemicals. Bentham Science Publishers Ltd, USA, pp 63–87 2008-0844 Sánchez-Bayo F, Goka K (2005) Unexpected effects of zinc pyrithione US EPA (2012) United States Environmental Protection Agency and imidacloprid on Japanese medaka fish (Oryzias latipes). Aquat Ecological Risk Assessment. http://www.epa.gov/oppefed1/ Toxicol 74:285–293 ecorisk_ders/toera_analysis_eco.htm. Accessed 27 Oct 2012 Selås V, Steen R, Kobro S, Lislevand T, Stenberg I (2008) Direct and indirect Van Dijk T, Van Staalduinen MA, Van der Sluijs JP (2013) Macro- weather impacts on spring populations of lesser spotted woodpecker invertebrate decline in surface water polluted with imidacloprid. (Dendrocopos minor)inNorway.ScandJForRes23:148–153 PLoS ONE 8:e62374. doi:10.1371/journal.pone.0062374 SERA (2005) Imidacloprid—human health and ecological risk assess- Watkinson AR, Freckleton RP, Robinson RA, Sutherland WJ (2000) ment—final report. Report from Syracuse Environmental Research Predictions of biodiversity response to genetically modifed Associates to USDA, Forest Service herbicide-tolerant crops. Science 289:1554–1557 Simons LS, Martin TE (1990) Food limitation of avian reproduction: an Whitehorn PR, O’Connor S, Wackers FL, Goulson D (2012) experiment with the Cactus Wren. Ecol 71:869–876 Neonicotinoid pesticide reduces bumble bee colony growth and Siriwardena GM, Ballie SR, Crick HQP, Wilson JD (2000) The impor- queen production. Science 336:351–352 tance of variation in the breeding performance of seed-eating birds Wirth EF, Pennington PL, Lawton JC, DeLorenzo ME, Bearden D, in determining their population trends on farmland. J Appl Ecol 37: Shaddrix B, Sivertsen S, Fulton MH (2004) The effects of the 128–148 contemporary-use insecticide Firponil in an estuarine mesocosm. Sotherton N, Holland J (2002) Indirect effects of pesticides on farmland Environ Pollut 131:365–371 wildlife. In: Hoffman DJ, Rattner BA, Allen Burton G, Cairns J Zanette L, Clinchy M, Smith JNM (2006) Combined food and predator (eds) Handbook of ecotoxicology, 2nd edn. CRC Press Ltd, USA, effects on songbird nest survival and annual reproductive success: pp 1173–1196 results from a bi-factorial experiment. Oecol 147:632–640